Summary of work: Adult bone loss is a universal phenomenon, and may lead to bone fracture and osteoporosis. This project investigates the epidemiological, genetic, cross-sectional, longitudinal and cross-cultural aspects of bone loss among participants of the BLSA, and among genetic isolates from Europe, Japan, Australasia, Central America and Africa. As part of our ongoing studies of bone status in the BLSA population, we examined the association between femoral neck bone mineral density (femBMD) measured by dual energy x-ray absorptiometry (DEXA),and radial BMD measured by single photon absorptiometry (SPA) and measures of obesity and diabetes (BMI, fasting glucose, and fasting insulin levels). Fasting insulin levels were correlated with BMD in the hip, but not in the radius. After accounting for the effects of weight in the weight bearing joint of the hip, there was no independent effect of insulin on bone mineral density in either the radius or the hip. This is in contrast to reported relationships in diabetics, and indicates that in a normal population the loss of bone is not related to a metabolic process similar to diabetes.